Complications Following the Use of Biologic Mesh in Ileostomy Closure: A Retrospective, Comparative Study

Prophylactic placement of mesh in the abdominal wall during ileostomy closure can decrease the rate of hernia formation. However, few studies have evaluated the safety of biologic mesh in ileostomy closure. Purpose: This study aimed to investigate the safety of biologic mesh in ileostomy closure, specifically the need to remove the mesh due to infection. The rate of surgical site infection (SSI), incisional hernia, surgical site occurrence ([SSO] including seroma and hematoma), and wound pain between primary closure and mesh closure groups also were investigated. Methods: Using a retrospective study design, data from all consecutive patients who underwent ileostomy closure from January 2015 to June 2016 at the Hanyang University Hospital, Seoul, Republic of Korea, were analyzed. Patients with stage IV colorectal cancer, who were older than 85 years, or who experienced intestinal perforation during the procedure were excluded. Demographic (age, sex, body mass index [BMI], underlying disease) and clinical characteristics as well as SSI, SSO, length of hospital stay, use of additional analgesics, white blood cell count, C-reactive protein, and visual analog scale (VAS) pain scores (noted on days 1, 3, 5, and 14) were abstracted and compared. Clinical and surgical variables were compared using the Mann-Whitney U test, the χ2-test, or Fisher’s exact test, depending on the nature of the data. Results: Of the 38 patients who underwent ileostomy closure, 33 (18 [54.5%] who received primary closure and 15 [45.5%] who received mesh closure) were included for analysis. Patient, surgical, and clinical characteristics were not significantly different, but the mean age of the primary closure group was significantly higher than that of the mesh closure group (71 ± 9 vs. 62 ± 10 years old; P = .014). The median follow-up duration was 25 months (interquartile range 18.0–31.5 months). Six (6) complications were observed in 5 patients in the primary closure group, and 8 complications in 5 patients were noted in the mesh closure group (27.8% vs. 33.3%; P = 1.000). None of the cases required removal of the biologic mesh due to mesh-related infectious complication. Two (2) SSIs occurred in the primary closure group (11.1% vs. 0%; P = .489). Three (3) patients experienced a postoperative incisional hernia (9.1%) — 1 in the primary closure group and 2 in the mesh closure group (5.6% vs. 13.3%; P = .579). No statistically significant differences in pain or length of hospitalization were noted. Conclusion: No mesh-related infectious complications required biologic mesh removal, and no significant differences were noted in SSI, incisional hernia, and wound pain between the primary closure and mesh closure groups. Although not significantly different, the higher rates of hernia and SSOs in the mesh group require further study. 

A diverting ileostomy is widely used to reduce the number of serious complications such as sepsis and mortality caused by leakage after low rectal resection. For example, in a randomized multicenter trial,¹ 12 of 116 patients (10.3%) with a stoma and 33 of 118 without a stoma (28.0%) experienced leakage after low anterior resection (odds ratio [OR] = 0.30; 95% confidence interval [CI], 0.17–0.59; P < .001). Consistent with this result, a systematic review² showed a stoma successfully prevented anastomotic leakage in patients undergoing low anterior resection (OR = 0.32; 95% CI, 0.17–0.59; P = .003).²

A stoma is a surgically created artificial opening between one hollow organ and the outside of the body in the abdominal wall. Therefore, the stoma site is essentially a hernia, characterized by a full-thickness defect in the abdominal wall with protrusion of the abdominal contents. After the distal process has resolved, stoma closure is required, resulting in pain and potential complications such as wound infection and incisional hernia; the latter is the most serious complication. A systematic review³ of 18 studies (1316 patients) found that the overall mean incisional hernia rate following ileostomy closure was 4% (range 0–33%). A systematic review⁴ of 3 studies (284 patents) with low risk of bias found the incidence of incisional hernia following ileostomy closure was closer to 30%. Although several risk factors for postoperative hernias have been identified (eg, age, malignancy, diabetes, chronic obstructive pulmonary disease, hypertension, obesity), these factors are not easily correctable.⁵ Therefore, operative technique might be the cornerstone for preventing hernia formation after ileostomy closures. In this setting, prophylactic placement of mesh in the abdominal wall during the ileostomy closure may be a practical option to decrease the rate of hernia formation.

Randomized controlled trials^6,7 have found that in midline laparotomy closure, a significant reduction in the incidence of incisional hernia was achieved with onlay prosthetic mesh reinforcement compared with primary closure without increasing surgical site infection (SSI). However, due to lack of data, guidelines⁸ make no recommendation as to the type of mesh for prophylactic mesh augmentation in midline laparotomy closure. Some retrospective studies^9,10 have reported that prosthetic mesh placement significantly reduced the incidence of an incisional hernia in ileostomy closure without increasing complication rates. However, because the number of patients in these studies was small and the site of stoma and measured outcomes were heterogeneous, evidence is lacking; likewise, few studies, to the authors’ knowledge, have evaluated the safety and use of biologic mesh in ileostomy closure.^11–13 Therefore, the safety and efficiency of biologic mesh to reduce the hernia of the stoma site warrants study.

This study aimed to investigate the safety of biologic mesh in ileostomy closure, specifically regarding the need to remove the mesh due to infection. The rate of SSI and incisional hernia and the amount of wound pain between primary closure and mesh closure groups were also investigated.

Patients and enrollment. A retrospective study including consecutive patients who underwent ileostomy closure between January 2015 and June 2016 at the Hanyang University Hospital, Seoul, Republic of Korea, was conducted. Data from patients with stage IV colorectal cancer, patients older than 85 years, and patients who experienced intestinal perforation during the procedure were excluded. Reasons for exclusion were as follows: patients with stage IV colorectal cancer were excluded because they could not attend regular follow-up visits in the clinic, patients older than 85 years were excluded because advanced age is a risk factor for incisional hernia, and patients who experienced intestinal perforation during the procedure were excluded because of possible wound contamination. General surgical consent for the use of mesh was obtained from all patients. This study was approved by the Institutional Review Board of Hanyang University Medical Center (IRB No. 2018-12-032).

Surgical procedures. Two (2) surgeons performed an equal number of surgeries using the same surgical approach. Prophylactic preoperative intravenous antibiotics were administrated at induction of anesthesia. The proximal loop was sutured using a purse-string stitch with 2-0 black silk to prevent leakage of the ileal content onto the surgical field during the procedure. A trephine incision was made after the skin around the ileostomy site was prepared. The ileal anastomosis was performed using sutures or stapling devices according to the surgeon’s preference. The tissue plane just superficial to the aponeurosis surrounding the fascial closure was dissected. The decision to use biologic mesh was based on the surgeons’ preference. In all cases, the fascia and soft tissue were cultured for microbiological organisms, and Jackson-Pratt wound drains were inserted between the skin flap and the fascia. Skin closure was performed using a 2-0 polypropylene (Prolene, Ethicon) interrupted suture.

The fascia was closed by continuous suture using 1-0 polyglyconate copolymer sutures (Maxson, Covidien) in the primary closure group. The drain was removed when the output was less than 20 mL/day for 2 consecutive days in the primary closure group.

If it was determined that a biologic mesh was going to be used, a 2 x 3 cm or 4 x 7 cm non-crosslinked porcine dermal biologic mesh (XCM Biologic Tissue Matrix, Johnson & Johnson Medical) was selected according to the size of the fascial defect in the mesh closure group. The mesh was placed anterior to the rectus sheath onlay. Transfascial bites were 

anchored using 2-0 polydioxanone (PDS, Ethicon) sutures taken circumferentially (Figure 1). The drain was removed on postoperative days (PODs) 2 or 3 regardless of the amount of output in the mesh closure group because the mesh was water-permeable. For 3 to 5 days, a compressive dressing was applied to facilitate healing between the skin flap and the fascia and mesh in the mesh closure group.

Study endpoints and definitions. The primary endpoint of the study was the safety of the biologic mesh defined as the need for mesh removal due to mesh-related infectious complication. Secondary endpoints included SSI, incisional hernia, and wound pain. The definition of the SSI followed the Centers for Disease Control and Prevention Guidelines,¹⁴ which state that SSI is an infection that occurs within 30 days after the operative procedure if no implant is left in place or within 1 year if an implant is in place and the infection appears to be related to the operative procedure. Surgical site occurrence (SSO) was defined as surgical site seroma and hematoma. The presence of an incisional hernia was determined by physical examination and imaging studies. To determine the presence of hernia, physical examination was performed in both the standing and supine positions for all patients by assessing increased abdominal pressure using the Valsalva maneuver. On physical examination, the hernia was defined as bulging during the Valsalva maneuver and by palpation of the fascial defect. Morbidity was classified using the Clavien-Dindo system¹⁵; of most relevance to this study, Clavien-Dindo grade III was defined as a complication that required surgical, endoscopic, or radiological intervention.

White blood cell (WBC) counts and C-reactive protein (CRP) levels were measured on PODs 1, 3, and 5. A visual analog scale (VAS) was used for pain evaluation. VAS scores were measured on PODs 1, 3, 5, and 14.

Follow-up and data collection. Clinical follow-up was undertaken in the hospital outpatient clinics of the respective surgeons. Patients visited the outpatient clinic 2 weeks, 1 month, and 6 months after stoma reversal. In addition, patients underwent computed tomography (CT) scans every 6 months during the follow-up period.

The authors collected the data by reviewing electronic medical records. In addition to the outcome variables, abstracted data included demographics (eg, age, sex, body mass index [BMI], underlying disease) and surgical data (type of index operation, purpose of index operation, surgical approach of index operation, operation time, and length of hospital stay). Index operation was defined as the operation at the time of the creation of the ileostomy. Patients were categorized as using additional analgesics if they were administered acetaminophen, nonsteroidal anti-inflammatory drugs, or narcotic analgesics, even once during hospitalization, intravenously.

Statistical analysis. The statistical data were coded electronic medical records to SPSS by manual entry. Continuous variables were presented as mean ± standard deviation. Categorical variables were presented as frequency (%). Clinical and surgical variables were compared using the Mann-Whitney U test, the χ2-test, or Fisher’s exact test, depending on the nature of the data. A P value < .05 was considered statistically significant. Statistical analyses were conducted with SPSS version 18.0 (SPSS Inc).

Clinicopathological characteristics. Of the 38 patients who underwent ileostomy closure, 33 were included in the analysis. Eighteen (18) patients (54.5%) received primary closure, and 15 (45.5%) received mesh closure. There were 5 patients excluded in the analysis as follows: 2 patients had stage IV colorectal cancer, 1 patient was older than 85 years, and 2 patients experienced intestinal perforation during the procedure. The 2 groups did not differ significantly except for age; the age of the primary closure group was significantly higher than that of mesh closure group (71 ± 9 vs. 62 ± 10 years old, P = .014) (Table 1). The most common indication for stoma formation was colorectal malignancy (27 patients [81.8%]). Twenty (20) patients (60.6%) underwent laparoscopic surgery. The median time between the index operation and ileostomy closure was 4.8 months (interquartile range [IQR] 2.3–7.4 months). The median follow-up duration was 25 months (IQR 18.0–31.5 months) in both groups; the median follow-up duration was 22 months (IQR 20–30 months) in the mesh closure group and 26.5 months (IQR 15.5–33.0 months) in the primary closure group, respectively. The 1-year and 2-year follow-up rate in both groups was 90.9% and 57.6%, respectively.

Surgical outcome. None of the cases required mesh removal due to mesh-related infectious complication, and postoperative morbidity rates were not significantly different between the 2 groups. Six (6) complications occurred in 5 patients in the primary closure group, and 8 complications occurred in 5 patients in the mesh closure group (27.8% vs. 33.3%, P = 1.000). Two (2) patients in the primary closure and no (0) patients in the mesh closure group developed an SSI (11.1% vs. 0%, P = .489). One (1) SSO occurred in the primary closure and 3 SSOs in the mesh closure group (5.6% vs. 20.0%, P = .308). Among the 33 patients, postoperative incisional hernias developed in 3 patients (9.1%)—1 in the primary closure and 2 in the mesh closure group (5.6% vs. 13.3%, P = .579). All incisional hernias were detected in the image evaluation, and 1 was found in the physical examination at the same time. The duration between ileostomy closure and incisional hernia detection in the 1 primary closure and 2 mesh closure patients was 12, 13, and 18 months, respectively. Two (2) Clavien-Dindo grade III complications occurred in the mesh closure group: 1 patient underwent adhesiolysis owing to postoperative ileus, and the other underwent surgery for an incisional hernia. There was no Clavien-Dindo grade III in the primary closure group.

Analgesic use. Nine (9) patients in the primary closure and 9 patients in the mesh closure group used additional analgesics (50.0% vs. 60.0%, P = .729). The average length of hospital stay in the mesh closure group was shorter but the difference was not significant (10.0 ± 4.8 vs. 7.2 ± 2.0 days, P = .073) (Table 2).

WBC counts and CRP levels. No statistically significant difference was noted in WBC counts at PODs 1, 3, and 5 (10.4 ± 3.7 vs. 8.3 ± 2.8 × 103/mm³, P = .092; 7.4 ± 3.1 vs. 5.7 ± 1.6 × 103/mm³, P = .069; and 5.9 ± 1.4 vs. 5.3 ± 1.7 × 103/mm³, P = .304, respectively). CRP level was not significantly different at PODs 1 and 3; a statistically significant difference was noted on POD 5 (4.9 ± 5.0 vs. 3.6 ± 2.4 mg/dL, P = .361; 8.5 ± 5.4 vs. 5.6 ± 2.7 mg/dL, P = .071; and 4.6 ± 2.3 vs. 2.5 ± 1.5 mg/dL, P = .009, respectively). No significant difference was noted in VAS scores at PODs 1, 3, 5, and 14 (7.0 ± 2.2 vs. 5.2 ± 2.0, P = .095; 5.7 ± 2.0 vs. 4.7 ± 1.6, P = .127; 4.2 ± 2.2 vs. 4.4 ± 1.3, P = .784; and 1.8 ± 1.7 vs. 2.0 ± 2.1, P = .739, respectively) (Figure 2).

Microbiological culture results. Positive results were found in 7 cases (21.2%) and included Staphylococcus epidermidis (4) and Enterococcus coli (3). Bacteria were cultured in 4 patients in the primary closure group and in 3 patients in the mesh group. However, the bacteria cultured group did not develop SSIs.

To the authors’ knowledge, few previous studies have evaluated the safety and efficiency of biologic mesh in ileostomy closure. In a case series, Bhangu et al¹¹ reported that 7 patients who received biologic mesh closure had no early adverse events during the 30-day follow-up. In the Reinforcement of Closure of Stoma Site randomized controlled trial¹² that compared primary and biologic mesh closure (n = 45 patients in each group), no mesh-specific complications occurred during the 30-day follow-up. In their blinded, case-matched study, Maggiori et al¹³ reported that the chance of hernia formation was lower among 30 patients who received biologic mesh during 16.8 ± 3.3 months follow-up compared to 64 patients who underwent primary closure, and no SSIs occurred in the biologic mesh group. Consistent with this result, no mesh-related infectious complications requiring mesh removal and SSI occurred in the mesh closure group in the current study. None of the 3 cases of SSO in the mesh closure group required surgical intervention. Based on these results, the current study provided evidence of the safety of incorporating biological mesh in ileostomy closure. In addition, given the previous studies demonstrating the placement of biologic meshes on the intraperitoneal space^11,12 or on the retromuscular plane,¹³ this study showed the technical feasibility of on-lay sutures, which was comparable with that of previous studies.

Prophylactic placement of mesh in ileostomy closure could reasonably be expected to reduce the incidence of incisional hernia. In the current study, incisional hernia occurred in 2 cases in the mesh closure group and in 1 case in the primary group. Although not statistically significant, the incisional hernia rate was more than double in the mesh closure group. These results may be biased due to the small sample size, and large-scale studies are needed. In the present study, the overall postoperative incisional hernia rate was 9.1%. The incisional hernia rate of the present study is relatively lower than that of previous studies, which reported the rate closer to 30%.⁴ Patient group characteristics in the current study may explain this lower rate. In previous studies, obesity was known to be a risk factor for the incidence of incisional hernia.^16,17 In particular, Schreinemacher et al¹⁸ reported that a BMI of 30 or higher was the only risk factor. However, the mean BMI of patients included in the current study was less than 23. The lower BMI may have contributed to the relatively lower incisional hernial rate. In addition, the occurrence of an incisional hernia was determined by physical examination and by imaging studies. Previous retrospective comparative studies^19,20 indicated that the detection rate was higher when image evaluation was performed rather than with clinical examination alone. Based on these results, the current study approach involved a relatively accurate evaluation of the incisional hernia rate.

It could be assumed that tension on the abdominal wall is the cause of the pain following ileostomy closure; hence, the use of mesh could decrease such tension and pain compared with primary closure. However, no statistically significant difference was noted in VAS scores and the use of additional analgesia. Only the length of hospital stay among patients in the mesh closure group was shorter than that of the primary closure group, but the difference was not statistically significant. Thus, evaluation of pain using a detailed scale that assesses intensity and duration is necessary.

The biologic mesh was thought to resist infection utilizing an acellular collagen matrix mechanism that allows neovascularity and ingrowth by native fibroblasts, with gradual incorporation and replacement of the mesh by the host tissue.²¹ However, a systematic review²² could not conclude that that biologic mesh was superior to prosthetic mesh in clean-contaminated fields due to a lack of available evidence. Studies regarding ileostomy closure have compared prosthetic mesh and biologic mesh with primary closure.^9–13 However, to the authors’ knowledge, no direct comparison was made between the 2 types of mesh. Such research is warranted.

The current study had several limitations. First, the accuracy of data is a limitation inherent in retrospective studies. The study is also limited by a small sample size and short follow-up period for hernia evaluation. Finally, because 2 surgeons performed the operations, the surgical outcome may vary depending on each surgeon’s preferences and skills. 

A retrospective evaluation of the safety of biologic mesh for use in ileostomy closure showed that no mesh-related infectious complications occurred that required biologic mesh removal. SSI, incisional hernia, and wound pain were not significantly different between primary closure and mesh closure groups. Further large-scale, randomized controlled studies are needed because of the observed high incidence of hernia in the mesh closure group.

Dr. JH Lee is a doctor, clinical assistant professor, Department of Surgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Republic of Korea. Dr. Ahn is a doctor, associate professor, and Dr. KH Lee is a doctor, professor, Department of Surgery, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, Republic of Korea. Please address correspondence to: Kang Hong Lee, MD, PhD, Department of Surgery, Hanyang University Hospital, Hanyang University College of Medicine, Wangsibri-ro 222-1, Seoungdong-gu, Seoul, 04763, Republic of Korea; email: leekh@hanyang.ac.kr. 

Potential Conflicts of Interest: none disclosed